Imbricated package of closed-end bags

ABSTRACT

An imbricated package of closed-end bags comprising a plurality of bags arranged so that each preceding bag overlies the top end of the following bag, an adhesive support member for the bags where each bag prior to the last, bottom bag is releasably adhered at its top end to the support member, each bag including (a) a seal for releasably sealing the bag at its top end and (b) adhesive means disposed on the outer surface of the bag above the seal, the adhesive means releasably securing each bag to the underside of the bag preceding it, the strength of the adhesive connection established by the adhesive means being greater than that of the seal so that as each preceding bag is removed from the package, the seal is peeled open to open the following package, and the strength of the adhesive connection between the following bag and the support member being greater than that established by the adhesive means so that the following bag is not removed from the support as the preceding bag is removed from the package.

United States Patent [191 Farrelly et al.

[ Oct. 28, 1975 IMBRICATED PACKAGE OF CLOSED-END BAGS [75] Inventors: Walter M. Farrelly, Wilmington,

' Del.; Sol J. Perlman, Towson, Md.

[73] Assignee: Vac-Pac Manufacturing Co.,

Baltimore, Md.

[22] Filed: Oct. 7, 1974 [21] Appl. No.: 512,853

Primary Examiner-William T. Dixson, Jr. Attorney, Agent, or Firm-Gerald J. Ferguson, Jr.; Joseph J. Baker [57] ABSTRACT An imbricated package of closed-end bags comprising a plurality of bags arranged so that each preceding bag overlies the top end of the following bag, an adhesive support member for the bags where each bag prior to the last, bottom bag is releasably adhered at its top end to the support member, each bag including (a) a seal for releasably sealing the bag at its top end and (b) adhesive means disposed on the outer surface of the bag above the seal, the adhesive means releasably securing each bag to the underside of the bag preceding it, the strength of the adhesive connection established by the adhesive means being greater than that of the seal so that as each preceding bag is removed from the package, the seal is peeled open to open the following package, and the strength of the adhesive connection between the following bag and the support member being greater than that established by the adhesive means so that the following bag is not removed from the support as the preceding bag is removed from the package.

14 Claims, 5 Drawing Figures Sheet 1 of 3 U8. Patent 0a. 2a, 1975 FIG.I

Sheet 2 of 3 3,915,302

U.S. Patent Oct. 23, 1975 U.S. Patent Oct. 28, 1975 Sheet 3 of3 3,915,302

FIG. 3

\ rm w FIG. 4

FIG.5

IMBRICATED PACKAGE OF CLOSED-END BAGS CROSS-REFERENCE TO COPENDING APPLICATIONS Reference is hereby made to a copending United States patent application by Walter M. Farrelly entitled Imbricated Bag Loading Machine, filed on instant date herewith and assigned to the assignee of the present patent application, the foregoing, copending application being incorporated herein by reference.

BACKGROUND OF THE INVENTION to G. I-Iannon discloses such a bag package where a plurality of open-end bags are so arranged with respect to one another that each preceding bag overlies and closes the opening of the following bag. Each bag is removably attached to an underlying support which may comprise a pair of parallel strips where the top end of all bags prior to the bottom bag of the package is removably attached to the support. Because the bags are open-ended, they are subject to the introduction of contaminants therein which is undesirable when processing such products as food or the like. This is a particular problem in food processing plants where the level of contaminants tends to be rather high.

Other imbricated packages of open-end bags are disclosed in U.S. Pat. Nos. 3,587,843; 3,587,844; and 3,587,845 granted to R. Wing. In U.S. Pat. No. 3,587,843 the imbricated package of bags is releasably secured to a pair of parallel adhesive tapes in a manner similar to that disclosed in Hannon U.S. Pat. No. 3,161,347. In U.S. Pat. Nos. 3,587,844 and 3,587,845, rather than releasably attaching the bags to a pair of parallel tapes or the like, the bags are releasably attached to one another at the top ends thereof. That is, at the top end of all bags except the top, forwardmost bag, adhesive means are disposed adjacent both sides of the top end of the bag. These adhesive means releasably secure each preceding bag to the top end of the following bag beneath it. In U.S. Pat. No. 3,587,844, a pair of adhesive splotches disposed at the top end of the bags are utilized as the adhesive means while in U.S. Pat. No. 3,587,845 a pair of small swatches of twofaced adhesive members are utilized as the adhesive means. Not only are all of the bags in the Wing patents open-ended but also, in U.S. Pat. Nos. 3,587,844 and 3,587,845, it is difficult to transport the bag packages in a bag loading machine since no strips are available for moving the bags along.

SUMMARY OF THE INVENTION It is a primary object of this invention to provide an imbricated package of closed-end bags which prevent contaminants from entering the bags.

It is a further object of this invention to provide an imbricated package of closed-end bags where the bags of the package may be loaded on conventional bag loading machines without having to incorporate any modification to the machines.

It is a further object of this invention to provide an imbricated package of closed-end bags which may be readily transported in a bag loading machine.

It is a further object of this invention to provide an imbricated package of closed-end bags where each bag is opened as the bag preceding it is loaded with a product and removed from the package.

These and further objects and advantages of the invention will become more fully apparent from the following detailed description of the preferred embodiments, the appended claims and the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top plan view of an illustrative, closed-end bag in accordance with the invention.

FIG. 2 is a top plan view of an illustrative imbricated package of closed-end bags in accordance with the invention.

FIG. 3 is a cross-sectional view taken along line 3-3 of the imbricated package of FIG. 1 with a food product loaded in the uppermost bag of the package.

FIGS. 4 and 5 correspond to FIG. 3 and further illustrate how the following bag is opened as the preceding, loaded bag is removed from the bag package.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Reference should be made to the drawing where like reference numerals refer to like parts.

Referring to FIG. 1, an illustrative bag 10 in accordance with the invention is shown, which may be any kind of known plastic material or other material suitable for use as a bag. The bag may be conventionally sealed at the bottom thereof by any conventional seal such as a heat seal or a pressure-sensitive seal. Other seals such as those shown in U.S. Pat. Nos. 3,478,952; 3,578,239; 3,686,823 or 3,716,369, all of which are hereby incorporated herein by reference, may also be used. Single or multiple seals may be used. Thus, the bottom seal may include a peelable seal 12, which may comprise a thermoplastic adhesive and a high strength seal 14, which may comprise a thermosetting adhesive, as shown in abovementioned U.S. Pat. No. 3,478,952. Although the top end 16 is shown to be straight, it may also be curved in the same manner as the bottom end 17 of the bag.

In order to close top end 16 of the bag, a preferably peelable seal 18 is provided which may comprise a seal of the same type as those mentioned above for the bottom of the bag. If bag 10 is made from a polyethylene therephthalate film, a thermoplastic adhesive for seals 12 and 18 may be used which exhibits adhesive characteristics for such films. Particularly preferred thermoplastic polyester adhesives, for example, are described in the Chapman U.S. Pat. No. 3,142,434, the disclosure of which is hereby incorporated by reference. Among other thermoplastic adhesives may be mentioned, by way of example, and not of limitation, the polyamide adhesives disclosed in U.S. Pat. No. 2,379,413, especially those of molecular weights of 6,000 to 9,000 and produced by the reaction of dimerized linoleic acid and ethylenediamine. Other thermoplastic adhesives for polyethylene terephthalate are known to the art and may be utilized.

Disposed on the outer surface of bag 10 at the top end thereof is an adhesive means 20, which, as will be brought out in more detail hereinafter with respect to FIGS. 3 and 4, is utilized to initiate the opening of bag 10. Adhesive means 20 may be of any known type of adhesive and may be of the same type as that of seal 18.

As can be seen in FIG. 2, seal 18 is preferably upwardly pointed to facilitate the opening of the bag, as will be described in more detail hereinafter. An upwardly arcuate configuration is also preferred. However, the bag may be sealed at its top end by a seal of any configuration including one that extends straight across and parallel to the top edge of the bag. It should be further noted that adhesive means 20 may comprise, for example, an adhesive splotch disposed on bag 10 or a swatch of a two-faced adhesive member disposed on bag 10 or any other adhesive means known to the art. As shown in FIG. 2, adhesive means 2% is preferably disposed above the apex of pointed seal 18. However, any other disposition of adhesive means 2% with respect to seal 18 would also be in accordance with this invention.

Reference should now be made to FIG. 2 where bag it is shown as the topmost, forward bag of an imbricated package of three closed-end bags. Of course, the number of bags is arbitrary. The bottom seals corresponding to seals 12 and 14 are not shown in FIG. 2 for purpose of clear illustration. A bag 30 is disposed beneath and behind bag 10 and includes seal 32 and adhesive means 34 respectively corresponding to seal 13 and adhesive means 20 of bag it A bag 49 also includes corresponding seal 42 and adhesive means 44. The bags prior to last bag 46 are releasably adhered at their top ends to a support which may comprise a pair of adhesive tapes t) and 52, the bags being connected to tapes 5t) and 52 in a manner which is known in this art.

As can be seen, adhesive means 34 releasably adheres the lower side of bag to the upper side of bag 30 while adhesive means 44 releasably adheres the lower side of bag 3% to the upper side of bag 44. As will be brought out in more detail hereinafter with respect to FIGS. 3 and 4, bag 36, for example, is opened as bag 10 is removed from tapes 50 and 52 of the package. In order to facilitate the opening of bag 30, the strength of the releasable adhesive connection between adhesive means 34 and bag 10 must be greater and preferably at least 143% greater than that of seal 32 so that seal 32 will be peeled open as bag 10 is removed from the package. However, the strength of the adhesive connection between adhesive means 34 and bag 10 must not be so great as to remove bag 36 from adhesive support tapes 5G and 52, as bag 10 is being removed. Thus, the strength of the adhesive connection between tapes S0 and 52 and bag 30 must be greater and preferably at least 10% greater than the adhesive connection between adhesive means 34 and bag it).

The foregoing will now be further illustrated with respect to FIGS. 3, 4 and 5. In FIG. 3, a product 60 such as a turkey is shown loaded in top bag 10. Such products are usually manually loaded in loading machines such as those described in the abovementioned copending patent application or US. Pats. Nos. 3,161,347 or 3,587,843The seal 18 for top bag 10 may be manually peeled open to permit insertion of product 60 into bag 10. As can be appreciated, the depth of seal 18 is substantially exaggerated in FIG. 3, as are all other adhesive connections in FlGS. 3 5, so that the operation of the invention can be clearly described.

Bag 10 is releasably adhered to tape 50 via seal portion 62 while bags 30 and are respectively releasably adhered to tape by seal portions 64 and 66. Clearly, bags 10, 30 and 40 are normally in intimate, overlying relationship and each bag is in intimate contact with tape 50 at its top end portion. However, as stated above, the depth of seals and the spacing between bags has been exaggerated to illustrate the operation of the invention. As can further be seen in FIG. 3, bag 30 comprises an upper side 70 and a lower side 72, which are releasably sealed together at the top end of the bag by peelable seal 32 and at the bottom end thereof by seals 74 and 76, which respectively correspond to seals 12 and 14 of bag 10 of FIG. 1. Further, the upper side 70 of bag 3t) is releasably adhered to the lower side of bag 10 by adhesive means 34. In a similar manner, bag 40 includes upper side 80 and lower side 82, the top end of the sides being releasably sealed together by seal 42 and upper side 80 being releasably sealed to lower side 72 of bag 30 by adhesive means 44.

As the product is loaded into bag 10, the bag is manually removed from the bag package, as can be seen in FIG. 4. Since the adhesive strength of seal 34 is greater than that of seal 32, the removal of bag 10 will cause upper side of bag 30 to be peeled from seal 32 to thereby initiate the opening of bag 30 preparatory to the loading of the next product therein. Thus, as the seal 32 is peeled open, a generally Z-shaped configuration, as can be seen in FIG. 4, may be imparted to the top end of upper side 70, where the upper horizontal leg of the Z is attached to adhesive means 34, and the lower horizontal leg corresponds to that portion of upper side 79 which has not yet been peeled from seal 32. The apex of seal 32 is indicated at A in FIGS. 2 and 4 while the lowermost portions thereof are indicated at C in FIGS. 2 and 4 and also at C in FIG. 2. The points to which seal 32 has peeled away are indicated at B and B in FIG. 2 and at B in FIG. 4.

Removal of bag 10 from the package also disengages the bag from seal portion 62 of tape 50 as can be seen. Continued removal of bag 10 will eventually release the bag from the upper side 70 of bag 30, at which time bag 30 will be substantially opened. A continuous blast of air directed toward the opening of bag 30 will keep the bag open. Means for providing this continuous blast of air are described in detail in the beforementioned, copending patent application and form no part of the present invention. As bag 10 is removed from the package, as shown in FIG. 5, and even after the bag is completely removed, the top end of lower side 72 of bag 30 is still adhered to tape 50 via seal portion 66.

Thus, as stated hereinbefore, the strength of the adhesive connection established by adhesive means 34 is greater than the strength of the seal established between upper and lower sides 70 and 72 by seal 32 and thus bag 30 is readily peeled open as loaded bag 10 is lifted away from the bag package. However, the strength of seal 64 between the lower side 72 of bag 30 and adhesive tape 50 is greater than that of adhesive means 34. Thus, bag 30 is not prematurely removed from tape 50 at the time bag 10 is removed therefrom.

Referring to FIG. 2, and as stated hereinbefore, adhesive means 34 may comprise the same peelable material as that of seal 32. However, different adhesive materials may be used for seals 32 and 34. By utilizing the upwardly pointed configuration of seal 32, this seal is more readily peeled away as bag 10 is removed from tapes 50 and 52. Thus, referring to FIGS. 2 and 4, it can be seen that as upper side 70 of bag 30 is peeled away from upwardly pointed seal 32, the initial resistance to peeling occurs at only a single point, that is the apex A of the seal. As the seal continues to peel open, it will resist at essentially only two segments of seal 32. Thus, when the seal has been opened to the segments indicated at B and B, continuing resistance to further opening of the seal is exerted only at these two latter segments. Thus, by utilizing the upwardly pointed configuration of seal 32, it is possible to make the adhesive connection of adhesive means 34 substantially stronger than the adhesive connection established by seal 32 even though the width of adhesive means 34 (from D to D) may be less than that of seal 32 since the width of adhesive means 34 is greater than the sum of the widths of segments B and B where resistance to continued peeling of seal 32 occurs. Thus, the relative strengths of the adhesive connections required for seal 32, adhesive means 34 and adhesive tape 50, in accordance with the invention as described hereinbefore, may be established not only by the relative strengths of the adhesive materials but also by the relative total widths of the respective adhesive connections.

Adhesive means 20 on top bag 10 is not necessary and may be eliminated if desired as may seal 18 of bag 10. If it is desired to connect the bag package of FIG. 2 to another bag package, then seals 18 and 20 would be desirable to facilitate the connection between the bag packages. If seals 18 and 20 are provided for top bag 10, this bag can be manually peeled open prior to the bag loading operation as indicated hereinbefore with respect to FIGS. 3 5. Alternatively, the top bag 10 may merely be removed from the bag package to thereby open bag 30 in the manner described hereinbefore with respect to FIGS. 3 5 whereby bag 30 becomes ,the first bag to be loaded.

An operable illustrative embodiment of the invention as shown in FIGS. 1 and 2 may incorporate the following specifications, which are given by way of example and, not limitation:

polyethylene 'terephthalate; 18 inches high and I inches wide. polyester adhesive sold under the identification 46968 polyester" by DuPont (produced by the process of U .S. Pat. No. 3,142,434); l3/l6 inches wide. v thermosetting adhesive, based on a polyurethane resin, a two part adhesive system having the designation 712-602 and 7l3806, the latter being used in an amount corresponding to 5% by weight of the 7l2602. The 7I2-602 material is a polyol composition exhibiting a Brookfield viscosity at 77F of 400-600 cps. at 25% solids in methyl ethyl ketone. The 713-806 is a prepolymer, which is a 75% solid solution in methyl ethyl ketone exhibiting a viscosity of that of a medium syrup; 3/32 inches wide.

the same as seal 12; 1/16 inches wide and slanted at an angle of approximately 19 with respect to the horizontal.

bag 10 seal 12- seal 14 seal 18 adhesive means 20 the same as seal 18; applied as an approximately rectangular splotch 1 inch wide and 7/32 inches high. pressure-sensitive adhesive tape sold under the identification tape 866 by the Minnesota Mining and Mfg. Co.; 3/l6 inches wide.

tape 50 What is claimed is:

1. An imbricated package of closed-end bags comprising a plurality of bags arranged so that each preceding bag overlies the top end of the following bag; an adhesive support member for said bags where each bag prior to the last, bottom bag is releasably adhered at its top end to said support member;

each said bag including (a) a bag seal for releasably sealing the bag at its top end and (b) adhesive means disposed on the outer surface of the bag, said adhesive means releasably securing each bag to the underside of the bagpreceding it;

the strength of the adhesive connection established by said adhesive means being greater than that of said bag seal so that as each preceding bag is removed from the package, said seal is peeled open to open the following bag; and

the strength of the adhesive connection between said following bag and said support member being greater than that established by said adhesive means so that said following bag is not removed from said support as said preceding bag is removed from the package.

2. An imbricated bag package as in claim 1 where said adhesive means is disposed above said bag seal.

3. An imbricated bag package as in claim 2 where said bag seal has an upwardly directed configuration to facilitate the opening thereof as each said preceding bag is removed from the package.

4. An imbricated bag package as in claim 3 where said bag seal configuration is upwardly pointed.

5. An imbricated bag package as in claim 3 where said bag seal configuration is upwardly arcuate.

6. An imbricated bag package as in claim 3 where said adhesive means is disposed above the uppermost point of said bag seal to further facilitate the opening of said seal as said each preceding bag is removed from the package.

7. An imbricated bag package as in claim 6 where said adhesive means comprises a swatch of two-face adhesive material.

8. An imbricated bag package as in claim 6 where said adhesive means comprises a splotch of adhesive material, which is the same as the adhesive material comprising said seal.

9. An imbricated bag package as in claim 8 where the adhesive material comprising said adhesive means and said seal is a thermoplastic adhesive.

10. An imbricated bag package as in claim 9 where said bags are made from polyethylene terephthalate.

11. An imbricated bag package as in claim 3 where the width of said adhesive means in a direction parallel to the width of the bag is greater than the total width of said bag seal along any imaginary line parallel to said direction.

12. An imbricated bag package as in claim 1 where said support member comprises a pair of adhesive tapes disposed at the respective approximate sides of said bags.

13. An imbricated bag package as in claim 1 where said adhesive connection established by said adhesive means is at least 10% greater than that of said bag seal.

14. An imbricated bag package as in claim 13 where said adhesive connection between said following bag and said support member is at least 10% greater than that established by said adhesive means. 

1. An imbricated package of closed-end bags comprising a plurality of bags arranged so that each preceding bag overlies the top end of the following bag; an adhesive support member for said bags where each bag prior to the last, bottom bag is releasably adhered at its top end to said support member; each said bag including (a) a bag seal for releasably sealing the bag at its top end and (b) adhesive means disposed on the outer surface of the bag, said adhesive means releasably securing each bag to the underside of the bag preceding it; the strength of the adhesive connection established by said adhesive means being greater than that of said bag seal so that as each preceding bag is removed from the package, said seal is peeled open to open the following bag; and the strength of the adhesive connection between said following bag and said support member being greater than that established by said adhesive means so that said following bag is not remOved from said support as said preceding bag is removed from the package.
 2. An imbricated bag package as in claim 1 where said adhesive means is disposed above said bag seal.
 3. An imbricated bag package as in claim 2 where said bag seal has an upwardly directed configuration to facilitate the opening thereof as each said preceding bag is removed from the package.
 4. An imbricated bag package as in claim 3 where said bag seal configuration is upwardly pointed.
 5. An imbricated bag package as in claim 3 where said bag seal configuration is upwardly arcuate.
 6. An imbricated bag package as in claim 3 where said adhesive means is disposed above the uppermost point of said bag seal to further facilitate the opening of said seal as said each preceding bag is removed from the package.
 7. An imbricated bag package as in claim 6 where said adhesive means comprises a swatch of two-face adhesive material.
 8. An imbricated bag package as in claim 6 where said adhesive means comprises a splotch of adhesive material, which is the same as the adhesive material comprising said seal.
 9. An imbricated bag package as in claim 8 where the adhesive material comprising said adhesive means and said seal is a thermoplastic adhesive.
 10. An imbricated bag package as in claim 9 where said bags are made from polyethylene terephthalate.
 11. An imbricated bag package as in claim 3 where the width of said adhesive means in a direction parallel to the width of the bag is greater than the total width of said bag seal along any imaginary line parallel to said direction.
 12. An imbricated bag package as in claim 1 where said support member comprises a pair of adhesive tapes disposed at the respective approximate sides of said bags.
 13. An imbricated bag package as in claim 1 where said adhesive connection established by said adhesive means is at least 10% greater than that of said bag seal.
 14. An imbricated bag package as in claim 13 where said adhesive connection between said following bag and said support member is at least 10% greater than that established by said adhesive means. 